The Arctic ecosystem is located in northern regions including parts of Alaska, Canada, Finland, Greenland, Iceland, Norway, Russia and Sweden. It has cold winters and cool summers with low annual precipitation mostly in the form of snow. The habitat supports dwarf shrubs, grasses, herbs and mosses in the tundra. Common herbivores include Arctic hares, lemmings and caribou, while predators include snowy owls, Arctic foxes and wolves hunting on the land and polar bears hunting in the sea. Food chains transfer energy from plants through herbivores to carnivores.